"We further observe, that this fresh-water formation, which, according to our view, terminates the reign of the Gymnosperms is connected, by the whole of its characters with other epochs of the vegetation of the Jurassic formation, and is distinguished from the Cretaceous epoch, which succeeds it, by the complete absence of every species which could be arranged among the Angiospermous dicotyledons, both in France and England, as well as in the deposits of northern Germany, so rich in varied species. On the contrary, in the lower chalk, cretaceous _glauconia_, the quadersandstein or planerkalk of Germany, we immediately find many kinds of leaves evidently belonging to the great division of Angiospermous dicotyledons, as well as some remains of palms, of which no trace is observable in the Wealdean deposits. "I class among the Cycadeæ the stems of the Tilgate forest, formerly designated by the name of _Clatharia Lyellii_, and which I have considered as a stem related to the _Dracæna_. The whole of its characters, although the almost entire absence of the tissues prevents us examining its anatomy, appear to me to render this connection most probable, and particularly to indicate the relations between this stem and that of _Zamites gigas_ found at Scarborough. "The abundance of Lonchopteris Mantelli is a character of the Wealdean formations of the south of England and the department of the Oise, where this fossil seems to make its appearance, at least in fragments, in the greater number of localities, where these beds are exposed by the excavation of potter's clay in this formation, near Savignies. In Germany, on the contrary, this species is wanting, and _Abietites Linkii_ becomes the predominating plant. With regard to Brachyphyllum, I have not yet had it in my power to study them in a natural state; but the figures given of them leave little doubt as to their analogy with the species of the Oolitic epoch. "The abundance of the Cycadeæ likewise forms a distinctive character of the Wealdean formations of Germany. Still there are, as has been seen, many species common to the two basins; and I may add, that probably the Sphenopteris Goepperti, _Dunk._, does not differ from Sphenopteris Phillipsii, _Mant._ "I have not included in this list some marine plants mentioned as belonging to the beds of this epoch; _1st_, because it appears to me doubtful whether they really belong to the Wealdean and not to the Glauconian epoch; _2dly_, because it still appears to me uncertain, whether the species mentioned, Chondrites æqualis and intricatus, are quite identical, specifically with the species of this name belonging to the fucoidal sandstone lying above the chalk.